Electropneumatic braking system.



W. 0. MYERS. ELEGTROPNBUMATIC BRAKING SYSTEM.

APPLICATION FILED MAYZZ, 1913.

' 2 SHBBTS-SHEET 1.

Patented Dec. 16, 1913.

v a 5 M? Q 4 m m mw WITNESSES; @44 9 A TTORNE Y W G. MYERS.

ELEGTEOPNEUMATIG BRAKING SYSTEM. APPLICATION FILED MAY 22, 1913.

1,081,55)a Patented Dec. 16, 191 v 2 .E3HBETS-SHEET Z.

INVENTOR ATTORNEY i has been known that the motors could onrrnn OFFICE.

WILLIAM C. MYEBS'. or: oAKLAND, camroimm.

ELECTROINEUMATIC BRAKING SYSTEM.

Specification oi Letters Eatent.

Application filed May 22,- 1913.

Serial No. 769,331.

To all whom it may concern:

Be it known that I, WILLIAM C. MYERS, a citizen of the United States, residing at Oakland, in the county of Alameda and.

My invention relates to emergency braksystems for electric motor cars. It is especially adapted for cars fitted with multiple unit control. 'Ever since electric cars have been run e used to stop the car in the event of failure of power from the supply,- provided the connections to the motors were made so that if supplied withpower they would Propelthe car in the opposite direction from that in which the car is supposed to be running when it is desired to stop. original simple multiple connection of motors operated by a rheostat, the operation was merely to throw the reverse switch lever, .the braking action beginning automatically and independent of any further action on the part of the niotorman. This method has been used as an emergency braking device from the beginning of the art'down to the period when the so-called series-parallel control ticularly of the multiple unit type, where a number of cars, operated in a train, ,are controlled from one platform of that train. With the introduction of the multiple unit control of more recent years where independent switches eficct the necessary combinations of motors, and they themselves are controlled by secondary circuits in the hands of the motor-man, the old original practice of what was commonly known as slugging the motor was no longer possible when power to actuate these contactors or main switches was not available. This, and the introduction of more powerful and expensive air braking apparatus .on electric cars has diminished, if not. entirely in most cases prevented, the practice of slugging in emergencies. But, latterly, on account. 0 the desirability. of s when said cars are fitted with multiple unit control, it has become important to develop 'an emergency braking apparatus or system, other than an 'auxlhary of the air brakes,,

' In the oldand rates by a pipe 10, and the two was developed, paringlejlear operation, even and more particularly, way of mechanical connection between the braking system and the car wheels.

To this end my invention directs itself; and it consists 1n the novel electro-pneumatic braking system which I shall-now.

fully describe by reference to the accompanying drawings, in which- Figure of my system. Fig; 2 is a view showing the details of the electric switches and their airactuated instrumentalities. Fig. 3 is a detail view of the doublecheck-valve 17, showmg its environment. 1

' 1 are the car-wheels, 2 the gears, and 3 the pinions. The motors are designated by M M M and M.

4 is an air-supply reservoir which, under "the control of a. check valve 5, in the connection 6 from the main supply air-pipe'7, is adapted to contain air under pressure available at all times.-

8 aretwo air-valves, one of which is to be at each end of the car, and 9 are the handles Patented Dec. 16, 1913.

independent-in every 1 is a general diagrammatic view to operate said valves. \Vith one of-the air valves, the air-supply reservoir 4 communiair valves are in communication through the foul pipes 11.

12 is a polarity 13 are two cylinders, the piston-rods 14 of which operate the polarity switch. One of these cylinders communicates by a pipe 15 with one of the inter-valve pipes 11, and the other of said cylinders communicates with acid inter valvc pipe through a pipe 16. In said inter-valve pipe '11, between the connections therewith olithe pipes 15 and 16, is

switch,

adoublc-clieck valve 17, which, as shown in Figfl3, comprises an internal piston 18 with oppositely extending stems 19 each of which carries a valve 20 adapted to close and open alternately the air communications. from either air-valve to the polarity-switch-operating cylinders 13.

21 is a first electric-switch having three sinniltaneously operating contacts or nals. 22 is a second elcctric-switch having two successively operating conta'ctsor terminals. 23 is a third electric-switch similar to switch 22 with two successively operating termicontacts or terminals. ;-The details of these switches will be described later on by reference to Fig. 2:

24 is a first-position cylinder, the piston rod of which is adapted to operate the first electric-switch 21. This cylinder is connected by a pipe 26 with .the double check valve 17.

27 is a. second-position cylinder, the piston rod 28 of which is adapted to operate the second electric-switch 22. This cylinder supplied by a pipe 21) which issues from an equafixing-reservoir 30. Into this reservoir is admiilcd an air supply pipe 31 having an orifice 31 of restricted capacity, as seen in Fig. 2, said supply pipe 31 commimicatiug at its other end with a second'inter-rali'c pipe 11.

52 is a third-position-cylinder, the piston rod 33 of which 'is adapted to operate the third electric-switch 23, said cylinder being supplied by a pipe 34' leading from an equalizing-reservoirfii Into this reservoir is admitted an air-supply pipe 36 having an orifice 36' of a. capacity still more restricted, as shown in Fig. 2, than the capacity of the orifice 31 of the air supply pipe 31 leading into the equalizing-reservoir 30 of the second position cylinder 27. The air-supply pipe SGcox'nmimicates at its other end with a third inter-valve pipe 11.

The circuits through the first, second and third swit: es, the motors and the polarity switch are I). In the circuits b are the several resistances c, d, e, and f, and the'fields g, h, z, and\j. The grounds are at It; and Z.

we suppose the first switch 21 to be closed and the second and third switches 22 and 23 to be open, the circuitis from the'gronnd at is to the uppermost contact of the first switch; thence throughthe resistance e, thence through the resistance f, and thence to the polarity-switch 12; thence from said polarity switch, through the fields g and h and back to the polarity switch; thence out of said switch to the second motor M thence to the first motor M ,'aiid from said first motor to-the second contact of the first switch 21; thence through the'rcsistance c and through the resistance (l and back to the third contact of the first switch; thencc to the third motor M, and to the iourth motor 1 thence from the latter motor to the \polarity switch, and back from said switch to and through the fields y' and z' and to the polarity'switch again and finally to the ground Z. Now if we suppose the upper contact'of the second switch 22 to he later closed, while the first switch still remains closed, it will be seen that resistance a will be cut out; and similarly if still later the lower contact of the second switch 22 be closed, the resistance 7 will be cut out. v in like manner by the still later successive closing of the upper and lower contacts ot-the third-switch 23, thc resistances cand (1- will be successively cut out.

fect of this system, I shall point out by reference to Fig. 2, some of'the mechanical details of the switches.

The three switches 21, 22 and'23 together with their operating fluid-cylinders 2%, 2? and 32 are best housed in a switch box 37, the cylinder 21 and its switch 21 being shown as disposed between the other cylinders and switches. The piston 38 of said r \'lindcr is normally held up by a spring 238) as indicated. The piston rod 25 of this cylinder carries the three contact disks 40 in vertical series each yieldingly mounte and controlled by springs 41. The disks 40 are adapted to more to and from the contact. studs 1-2, and the arrangement is such that all contacts are made and broken simultaneonsly. 'lhc pisti'in 4-3 of thc second positionu-yliudcr 2? is likewise held up by a spring -14, and its rod 28\ carr1cs two contact disks :15, each yieldingiy mounted and third position cylinders are held down at their lowest positions by the automatically operating spring latches 48 adapted to engage huts 49 on the lower ends of said rods, said latches being released by the rods 50.

The operation may now be described. A sufficicnt supply of air is carried in the supply-reservoir 4, which air is available at all time owing to the check-valve 5. \Vhen it is desired to apply the brake, the air is admitted to the system by opening the air valve 8 at either end of the car. The oper; ating cylinders 13 of the polarity switch 12 and the first-position cylinder 2% of the first electrioswilch 21 are connected in parallel valve 17, the polarity switch 12 is 1'0"(-.1S(3(l from either end of the car regardless of any knc'iwlcdg'e on the part of the operator of the then position of said s\\'itch. Whcnthe air is thus admitted simultaneously to either one of the operating cylinders 13 of the polarity switch 12 and to the first position cylinder-"24 of the first ricctric-switch 21, the said polarilysnitch and the said first electric-switch are operated to make the electric connections to the motors required to cause one or more of them to-gcncrate current, while the others act as motors. 'lhisrcsults in a double retarding force on the car, one force being direct and due to the reversed action of that motor or motors acting as Before describing the operation and Bit- Eitlcll, and the other force being ndirect and.

due to the conversion of the momentum of the car into energy causing the otheiimotors toigenerate current. N ow, further, 1n order that the braking power thus obtained"may be automatically controlled, notwithstanding the decreasing momentum of the car, re-

sistances, as indicated at c, d, e, and f, are.

.Quired time in equalizing the pressure before operating the piston in said cylinder. The third-position cy1inder,32 is controlled similarly, its equalizin reservoir '35 being supplied by a stillsmaler orifice which requires more time for equalization.

I claim v v l.- An electro-pneumatic brakin system comprisingelectric motors; a supp y reservoir for air under pressure; apolarityswitch; an electric-switch; electric-circuits includin said motors,polarity-switch and electric-switch; an air-actuated instrumentality/for operating said polarityrswitch; a

- valves at separated separateair-actuated instrumentality for operating'the electric-switch; an air connection leading from the supply-reservoir operators oints in said connect-ion; separate branc connections leading from said air-connection, at points intermediate said valves, to said mstrumentalit1es;'

and means automatically controlling the communication of the branch connections with said air connection from either operators valve.

2. An electro-pneumatic braking system comprising electriemotors; a supply-reservoir for air under "pressure; a polarityswitch; an electric-switch; electric circuits including said, motors, polarity-switch and elcctric 'switch; a pairof air-actuated in,- struinentalities each adapted to operate the polarity-switch; a separate air-actuated instrumentality for operating the electricswitch; an air connection leading from the supply-reservoir; operators valves at separated. points in said connection; a vpair of branch connections each leading from said air-connection, at'points intermediate said valves, to the air-actuated instrumentalities of th polarity switch; 'a double-check valve in sa-ida r connectlon-between thecommunications therewith-of the said .pair of branch connections; and abranch-connection from 'sald valve to 0 rate the air-actuated instrumentality of t e electric-switch.

electro-pneumatic braking systemcomprising electric motors; a supply-reservoir for air under pressure; a polarit switch; an electric-switch; electric-circuits including said motors, polarity-switch and electric-switch; air-actuated instrumentalities for operating said polarity-switch and electric-switch air connections from the airsupply reservoir to operate said instrumentalities; an operators valve to control said connections, and means for automatically controlling the voltage and current during the brakin operation. c

4. An electro-pneumatic braking s'stem comprising electric-motors; a supply-reservoir for air under pressure; a polarityswitch; an electric-switch; electric-circuits including said motors, polarity-switch and electric-switch; said circuits having a resistance therein; airactuated instrumentalities for operating said polarity-switch and electrioswitch; air. connect-ions from the air- .su ply reservoir'to operate saidinstrumentafities; an opcrators valve to control said connections; and means for automatically cutting out the resistance in the electricicircuits during the braking operation.

5, An electro-pneumatic braking system comprising electricanotors; a supply-reservoir for air under pressure; a' iolarity switch; an electric-switch; electric-circuits including said motors, polarity-switch and electric-switch; said circuits having aplurality of resistances therein; air-actuated,

infstrumentalities for operating said polarityswitch and electric-switch; air connections from the air-supply reservoir to operate said instrumentalities; an cperators valve to control said connect-ions; and means for antomatically successively cutting out the 'rebraking operation.

(3. An electro-pneumatic braking system comprising electric-motors; a supply-reservoir for airunder pressure; a polarity switch; an electric-snitch: electric-circuits including said motors, polarity-switch and electric switch, said circuits having a resistaLce therein air-actuated instrumentalities for operating said polarity-switch and electrio-switch; air connections from the airsupply reservoir to operate said instrumentalities; an operators valve to control said connections; a second electric-switch; an electric circuit controlled by saidvsecond switch to cut out the resistance in the first 1 named circuits; an air-actuated instrument-ality to operate said second switch; and an air-connection from the first named air connections automatically operative to delay the action of the second switch. L

7. An electric-pneumatic braking'sy'stem comprising electric-motors; a supply-reser- -sistances in the electric circuits during the 105 'voir foi air under pressure; apolaritys'vvitch; an electric-switch; electric-circuits including sand motors, polarityswitch and electric-switch; said circuits having a resistance 'thereln; air-actuated mst-rumentalities for operating said polarity-switch and elec trio-switch; air I connection from the airsupply reservolr to operate said instrumentalltles; an operators valve to control said connections; a second electric-switch; an

electric circuit controlled by said second switch to cut out the resistance in the first named circuits; an airactuated instrumentality tooperate said second switch; and an air-connection from the first named air connections having included in it an equalizing reservoir automatically operative to delay the action of the second SWltCll.

8. An electrO-pneumatic braking system comprising electric-motors; a supp1y-reservoir'for airiunder pressure; a polarity switch; an ele'ctric-switch having a plurality emi simultaneously contacting terminals;

electric circuits including said motors, polarity-switch and electric-switch, said circuits hav ng a plurality of resistances therein; air-actuated inst-rumentalities for op-- matically operative to delay the action of.

said second switch.

In testimony whereor I have signed my name to this specificat on 1n the presence of two subscribing witnesses".

" WILLIAM G; M YERS.

' Tit-nesses:

WM. F. BOOTH, D. B. RICHARDS.- 

